<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        div{
            width: 100px;
            height: 100px;
            border:1px red solid;
        }

       .one{
           background-color: salmon;
       }
       .two{
           background-color: seagreen;
       }
       .three{
           background-color: violet;
       }


    </style>
</head>
<body>
    
    <div class='one'></div>
    <div class='two'></div>
    <div class='three'></div>

</body>
</html>